Electrical line system design, specifically the choice of a conductor to carry electrical current, is typically facilitated with two distinct sets of known calculations. Initially, a first computer program utilizes a first set of calculations to determine ampacity of a given conductor. Ampacity is a calculation of current carrying capacity for a conductor, given conductor temperature, and given a set of weather conditions.
Next, a second computer program computes sag and tension calculations for the transmission line. These calculations determine mechanical loads on the conductor, and other structures included in the transmission line system, under various weather conditions. The calculations also determine resulting conductor sag values. Typically, among the weather conditions evaluated, sag and tension values are calculated at the conductor temperature used for the ampacity calculation. This information is analyzed and used, for example, to determine the necessary height of towers that hold power lines.
Some software programs perform only one of these two calculations, while others perform both. Examples of such programs include that marketed by ACA Conductor Accessories, Spartanburg, S.C., under the trade designation “SAG10”, or that marketed by Power Line Systems, Inc., of Madison, Wis., under the trade designation “PLS-CADD”, or that marketed by Pondera Engineers, Spokane, Wash., under the trade designation “TL-PRO DESIGN STUDIO.”